Clinical context: A client was comfortable before a red-blood-cell transfusion. Twelve minutes after it began, the client reports sudden chills, severe low-back pain, and chest tightness. BP is 82/48 mm Hg, HR 128/min, RR 22/min, temperature 38.0°C (100.4°F), and SpO2 96% on room air. New dark-red urine appears in the catheter tubing. Lung sounds are clear, neck veins are flat, and there is no hives, wheezing, or facial swelling. The IV site is dry without swelling. Complete the diagram by selecting the condition the client is most likely experiencing, 2 actions the nurse should take to address that condition, and 2 parameters the nurse should monitor to assess the client's progress.

Quick answer
Acute hemolytic transfusion reaction. Stop the transfusion and infuse 0.9% saline through new tubing. Monitor hourly urine output and serum haptoglobin.

Why this is correct
Incompatible red cells are destroyed in the bloodstream within minutes, causing chills, flank or low-back pain, hypotension, and hemoglobinuria. Stopping the unit limits the dose of incompatible cells, and new tubing prevents flushing the rest of the unit into the vein. Free hemoglobin threatens the kidneys, so urine output is followed closely, and haptoglobin (low) with LDH (high) shows whether hemolysis continues.

Easy analogy or mental picture
Imagine the wrong key forced into a lock: the transfused cells are broken apart as they enter, and the pieces (free hemoglobin) clog the kidney's filters. Stop pushing keys in, and keep the filters flushed.

Memory hook
"Back pain + red urine = hemolysis: stop, new saline line, watch the urine."

NCLEX decision rule
When a serious transfusion reaction is suspected, the unit must not keep running, and IV access is maintained with saline through new tubing; choose monitoring that matches the specific reaction pattern.

Why the other choices are wrong
TACO causes hypertension, distended neck veins, and crackles, and the veins are flat with clear lungs, so furosemide and JVD track the wrong reaction. TRALI causes new hypoxemia with bilateral infiltrates, but SpO2 is 96% and lungs are clear, so chest films do not measure this problem. Anaphylaxis brings hives, wheezing, or swelling, which are absent, so IM epinephrine and urticaria checks do not fit. Slowing the rate with acetaminophen is the outdated response for a mild febrile reaction and continues giving incompatible blood.